Python HTTP 协议与 Web 框架

from urllib.request import urlopen, Request
from urllib.parse import urlencode
import json

# 简单的 GET 请求
response = urlopen('https://httpbin.org/get')
data = response.read().decode('utf-8')
print(f"状态码: {response.status}")
print(f"响应: {data[:200]}")

# 带 Headers 的请求
req = Request(
    'https://httpbin.org/get',
    headers={'User-Agent': 'Python Tutorial'}
)
response = urlopen(req)
print(f"\n带 Headers 请求状态: {response.status}")

# POST 请求
post_data = urlencode({'name': 'john', 'age': '30'}).encode('utf-8')
req = Request(
    'https://httpbin.org/post',
    data=post_data,
    headers={'Content-Type': 'application/x-www-form-urlencoded'},
    method='POST'
)
response = urlopen(req)
result = json.loads(response.read().decode('utf-8'))
print(f"\nPOST 响应: {result.get('form')}")

# 安装: pip install requests
import requests

# GET 请求
response = requests.get('https://httpbin.org/get')
print(f"状态码: {response.status_code}")
print(f"内容类型: {response.headers['content-type']}")
print(f"JSON 数据: {response.json()['url']}")

# 带参数
params = {'page': 1, 'limit': 10}
response = requests.get('https://httpbin.org/get', params=params)
print(f"\nURL: {response.json()['args']}")

# POST JSON
data = {'name': 'john', 'age': 30}
response = requests.post('https://httpbin.org/post', json=data)
print(f"\nPOST JSON: {response.json()['json']}")

# 自定义 Headers
headers = {'Authorization': 'Bearer token123'}
response = requests.get('https://httpbin.org/headers', headers=headers)

# 处理响应
response = requests.get('https://httpbin.org/get')
print(f"\n文本: {response.text[:100]}")
print(f"编码: {response.encoding}")
print(f"原始内容: {response.content[:50]}")

import requests

# 使用 Session 保持状态
session = requests.Session()

# 设置全局 Headers
session.headers.update({'User-Agent': 'MyApp/1.0'})

# 登录（示例）
# session.post('https://example.com/login', data={'user': 'john', 'pass': '123'})

# 后续请求自动携带 Cookie
# response = session.get('https://example.com/profile')

# Cookie 操作
response = requests.get('https://httpbin.org/cookies/set/name/john')
print(f"Cookie: {response.cookies.get('name')}")

# 发送 Cookie
cookies = {'session': 'abc123'}
response = requests.get('https://httpbin.org/cookies', cookies=cookies)
print(f"发送的 Cookie: {response.json()['cookies']}")

# WSGI 应用基本结构
def wsgi_app(environ, start_response):
    """最简单的 WSGI 应用"""
    status = '200 OK'
    headers = [('Content-Type', 'text/plain')]
    start_response(status, headers)
    return [b'Hello WSGI']

# ASGI 应用基本结构
async def asgi_app(scope, receive, send):
    """最简单的 ASGI 应用"""
    await send({
        'type': 'http.response.start',
        'status': 200,
        'headers': [[b'content-type', b'text/plain']]
    })
    await send({
        'type': 'http.response.body',
        'body': b'Hello ASGI'
    })

class SimpleRouter:
    """简单路由系统"""
    
    def __init__(self):
        self.routes = {}
    
    def route(self, path, methods=None):
        """路由装饰器"""
        methods = methods or ['GET']
        
        def decorator(func):
            self.routes[(path, tuple(methods))] = func
            return func
        return decorator
    
    def handle(self, path, method='GET'):
        """处理请求"""
        for (route_path, methods), handler in self.routes.items():
            if route_path == path and method in methods:
                return handler()
        return "404 Not Found"

# 使用
router = SimpleRouter()

@router.route('/', ['GET'])
def home():
    return "首页"

@router.route('/api/users', ['GET'])
def get_users():
    return "用户列表"

@router.route('/api/users', ['POST'])
def create_user():
    return "创建用户"

# 测试
print(router.handle('/'))
print(router.handle('/api/users', 'GET'))
print(router.handle('/api/users', 'POST'))

"""
RESTful API 设计规范

资源: /users          ← 用户集合
      /users/123      ← 单个用户

HTTP 方法映射 CRUD:
POST   /users         → 创建用户 (Create)
GET    /users         → 获取用户列表 (Read)
GET    /users/123     → 获取单个用户 (Read)
PUT    /users/123     → 更新用户 (Update)
PATCH  /users/123     → 部分更新 (Update)
DELETE /users/123     → 删除用户 (Delete)
"""

# 示例 API 响应格式
user_api_response = {
    "id": 123,
    "name": "张三",
    "email": "zhangsan@example.com",
    "created_at": "2024-01-15T08:30:00Z",
    "links": {
        "self": "/api/users/123",
        "orders": "/api/users/123/orders"
    }
}

# 集合响应格式
users_api_response = {
    "data": [
        {"id": 1, "name": "用户1"},
        {"id": 2, "name": "用户2"}
    ],
    "pagination": {
        "page": 1,
        "per_page": 10,
        "total": 100,
        "total_pages": 10
    },
    "links": {
        "first": "/api/users?page=1",
        "next": "/api/users?page=2",
        "last": "/api/users?page=10"
    }
}